Laser Bonding of Plastic Microfluidic Devices

Description

Development of microfluidic devices has proven successful in the lab. As quantities increase, plastic is the ideal material due to its relative low cost and inherent clarity. Advancements in through-transmission IR bonding now allow for plastic bonding of very small and sophisticated geometries. The assembly is accomplished without adhesives, vibration or the formation of particulate contamination. The laser mask-welding technology can create bond areas as narrow as 100 um. To accomplish this, freely definable geometries are generated on a metal-coated glass using the photolithographic process. Where the metal is etched away, the laser light is allowed to pass, transferring the pattern onto the substrate. Dedicated masks allow for flexibility, and an automatic alignment can precisely position the mask within ± 2 um. Laser welding is accomplished by passing laser light through a top, laser-transparent plastic material and onto a bottom, laser-absorbent material. The laser is absorbed and transformed into heat. With the parts clamped together, the heat is conducted into both components, creating a hermetic bond. Most thermoplastics can be joined with laser, including PC, PMMA and even COC or PEEK. Author: J. Zybko (Leister Technologies LLC)